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Mechanicsburg, Pennsylvania (CNN)Donald Trump called Hillary Clinton "the devil" on Monday as he rallied supporters in this battleground state.

Trump's extreme characterization of the Democratic presidential nominee came as he criticized Clinton's former presidential primary challenger Sen. Bernie Sanders of Vermont for endorsing Clinton.

"He made a deal with the devil. She's the devil," Trump said Monday as he rallied a rowdy crowd of supporters packed into a high school gymnasium.

Trump has accused Sanders several times in the last week of selling out by endorsing Clinton -- each time ratcheting up his words -- but his comment on Monday is the most direct comparison Trump has made between Clinton and the devil.

Speaking in Davenport, Iowa, last week, Trump accused Sanders of "selling out to the devil" by endorsing Clinton.

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And at a rally in Colorado on Friday, Trump said, "Bernie blew it. He sold his soul to the devil."

It's just Trump's latest foray into negative campaigning, coming just days after the GOP nominee said he was "starting to agree" with his supporters chanting "Lock her up" in reference to Clinton at a recent rally.

Meanwhile, Trump's labeling of Clinton as "the devil" follows his running mate, Indiana Gov. Mike Pence, recently saying he doesn't believe "name calling has any place in public life."